Q: I currently have a music library working on a laptop with an external hard drive. The hard drive stores the music I enjoy on an iPod classic. I would like to start a separate library of classical music to be used on another iPod classic. Can I use the same external hard drive to store both libraries? If so, how do I separate the two libraries? Do I have to run a second copy of iTunes on the computer to accomplish this/manage the music? I appreciate any help you can provide on this.

- Brad

A: You can definitely use the same external hard drive and same copy of iTunes to do this, although there are a couple of things to keep in mind for setting this up properly.

Firstly, it is important to keep in mind that iTunes distinguishes between the iTunes library database and the iTunes Media folder. Unless you’ve taken very specific steps to relocate your library database, it will live by default in an “iTunes” sub-folder under the “Music” folder for your user profile. By default, the iTunes Media folder lives in a sub-folder under the main iTunes folder, but can be located anywhere based on a setting found in the Advanced section of your iTunes preferences.

So unless you have already taken steps to specifically move your iTunes library database over to the external hard drive, it’s likely still living in its default location. This isn’t normally a problem as the iTunes database and related files don’t grow particularly large compared to your media content folder, but it’s important to keep in mind since this database contains all of your playlists and related track metadata and you should therefore ensure you’re backing it up regardless of what location it’s actually stored in.

To create a new iTunes library database, or switch to a different one, you can simply hold down the SHIFT key when starting iTunes; this will display a dialog box allowing you to either browse to an existing iTunes library database or specify a folder in which to create a new one.

You can create a new library database anywhere you like using this method, so if you want to store your second database on the external hard drive, simply create and select a folder in that location. Similarly, if you want to move your original library database over to the external hard drive, you can do this by shutting down iTunes, copying the “iTunes” folder over from “Music” and then using the “Choose Library” method to point iTunes to the new location. See our article on Transferring your iTunes Library for more information on this.

Each library database will have its own iTunes Media folder path, which will initially be set to the default location under the main iTunes library folder. Other library related settings are generally maintained separately for each iTunes library, such as which sections to display and options related to the iTunes Media folder. Likewise, sync information for iPods and iOS devices are also stored per-database, not per-computer, so each iPod classic will be able to sync to its own library, and should you accidentally connect an iPod classic with the wrong library open, you’ll get the usual warning about the device belonging to a different library, at which point you can choose to cancel the sync operation.

Keep in mind, however, that not all preferences are stored separately with each library. As a rule, library-related settings such as the iTunes Media folder and which media sections to display are stored for each library, while more general preferences such as playback settings are stored globally.